Grunt concat output ist empty

Question

My concat Task Output is empty, I don't understand it. my Gruntfile:

module.exports = function(grunt) {

    // Project configuration.
    grunt.initConfig({
        concat: {
            dist: {
                src: 'src/js/*.js',
                dest: 'js/main.js'
            }
        }
    });
    // Load Tasks
    grunt.loadNpmTasks('grunt-contrib-concat');

    // Default task.
    grunt.registerTask('default', 'concat');

};

grunt v0.4.5 npm v1.3.14

I use grunt concat and get the following message:

Running "concat:dist" (concat) task
File js/main.js created.

Done, without errors.

But the Outputfile main.js is empty.

Here is my package.json:

{
  "name": "Testing",
  "version": "0.0.0",
  "description": "",
  "main": "Gruntfile.js",
  "dependencies": {
    "bower": "~1.3.12",
    "express": "~4.10.2",
    "grunt-concat-include": "~0.2.4",
    "grunt-cli": "~0.1.13",
    "grunt-contrib": "~0.11.0",
    "grunt": "~0.4.5",
    "grunt-contrib-compass": "~0.7.2",
    "grunt-contrib-coffee": "~0.10.1",
    "grunt-contrib-compress": "~0.8.0",
    "grunt-contrib-connect": "~0.9.0",
    "grunt-contrib-concat": "~0.5.0",
    "grunt-contrib-csslint": "~0.2.0",
    "grunt-contrib-cssmin": "~0.9.0",
    "grunt-contrib-handlebars": "~0.8.0",
    "grunt-contrib-htmlmin": "~0.2.0",
    "grunt-contrib-imagemin": "~0.7.2",
    "grunt-contrib-jade": "~0.11.0",
    "grunt-contrib-jasmine": "~0.6.5",
    "grunt-contrib-clean": "~0.5.0",
    "grunt-contrib-jst": "~0.6.0",
    "grunt-contrib-copy": "~0.5.0",
    "grunt-contrib-jshint": "~0.10.0",
    "grunt-contrib-less": "~0.11.4",
    "grunt-contrib-requirejs": "~0.4.4",
    "grunt-contrib-qunit": "~0.4.0",
    "grunt-contrib-nodeunit": "~0.3.3",
    "grunt-contrib-sass": "~0.7.4",
    "grunt-contrib-uglify": "~0.4.1",
    "grunt-contrib-stylus": "~0.15.1",
    "grunt-contrib-yuidoc": "~0.5.2",
    "grunt-contrib-symlink": "~0.3.0",
    "grunt-contrib-watch": "~0.6.1",
    "grunt-dev-update": "~1.0.1",
    "grunt-express-server": "~0.4.19",
    "min": "~0.0.4"
  },
  "devDependencies": {},
  "scripts": {
    "test": "test"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/gruntjs/grunt"
  },
  "author": "me",
  "license": "BSD-2-Clause",
  "bugs": {
    "url": "https://github.com/gruntjs/grunt/issues"
  },
  "homepage": "https://github.com/gruntjs/grunt"
}

Just in case... Do you have any file in your `src` folder? I mean some js file in `src/js/` — dreyescat, Nov 24 '14 at 16:42
Yes is it, otherwise would not work... concat create a main.js File but it is Empty :( — , Nov 24 '14 at 23:09
I have exactly the same problem. Disappointing that no-one has any answers... — Inigo, Feb 19 '15 at 16:53
@ferdynator you added the "Solved" bit to the title but that's misleading! — tutuca, Sep 14 '16 at 05:56
@tutuca as you can see in the revisions (http://stackoverflow.com/posts/27108776/revisions) it was the user who did the edit. I agree it is misleading. — ferdynator, Sep 14 '16 at 10:05
@ferdynator my bad. I don't have enough rep to edit it. May you? — tutuca, Sep 14 '16 at 23:57
Try `grunt concat -v -d`, and see the console. [`-v -d`](http://gruntjs.com/using-the-cli) added for more information and to execute the task in debug mode. — Bhavik, Sep 15 '16 at 14:54

score 0 · Answer 1 · answered Jan 16 '20 at 10:38

The most likely cause for this is incorrect source paths. Everything must be relative from the location of the Gruntfile. In your case my guess would be that your Gruntfile resides inside of your src, so you need to change your config from:

concat: {
            dist: {
                src: 'src/js/*.js',
                dest: 'js/main.js'
            }
        }

to:

concat: {
            dist: {
                src: 'js/*.js',
                dest: 'js/main.js'
            }
        }

Grunt concat output ist empty

1 Answers1